In the U.S. and Europe, 15-20% of all full-time wage and salary workers work alternative shifts, with over 7 million Americans working on rotating or shift-work schedules. Shift work, in particular that which includes night work, accounts for 6.4% of all full-time wage and salary workers, and requires inverting the activity-rest cycle. As a resut, shift workers are more likely to experience sleepiness and insomnia, along with decreased productivity, impaired safety, diminished quality of life, and adverse health effects. Moreover, circadian disruption (including disruption of the melatonin cycle) due to rotating-shift work has been associated with in- creased risk for metabolic syndrome, diabetes, cardiovascular disease, and cancer. Shift work, including night shift work, is prevalent in the healthcare sector. Light ca help night- and rotating-shift workers to stay awake, due to suppression of melatonin, although melatonin suppression has been linked to increased risk for certain cancers. The PI demonstrated that short-wavelength (blue) and long-wavelength (red) light increases alertness, although only blue light significantly suppresses melatonin, suggesting melatonin suppression is not required for alertness and performance. The proposed study will field test promising laboratory results in a healthcare setting, testing the use of a novel lighting intervention (red light) to increase alertness and improve performance in healthcare rotating-shift workers without disrupting melatonin. If shown effective, non-pharmacological treatments to reduce errors in hospital settings and improve quality of lives for healthcare workers can be applied to help them cope with shift work without disrupting their circadian rhythms. In Aim 1, we will test the efficac and acceptance of red light exposure, delivered via personal light goggles in day-shift and rotating-shift workers in healthcare set- tings. In Aim 2, we will partner with Research to Practic (r2p) and other organizations to disseminate our findings, and will develop educational materials to inform end users, healthcare providers and designers of the state of current knowledge in the field through presenting results at conferences, writing articles in trade magazines, and developing videos for a website. While results obtained in this study are more relevant to the Healthcare and Social Assistance Sector Program, they can be applied in other industries, such as mining, transportation, and manufacturing, which are all areas of interest for the National Institute of Occupational Safety and Health (NIOSH).